The evolutionary significance of harem polygyny in the sand tilefish, Malacanthus plumieri: resource or female defence?

摘要: Abstract The sand tilefish occurs in colonies composed of polygynous mating units aptly characterized as harems. Field studies were conducted to examine the extent which male monopolize harems through defence resources important females, by directly restricting locations mates that aggregate reduce predation risk, or both. Burrow and female removals, combined with feeding experiments observation foraging prey distribution, indicated females defend a home burrow refuge surrounding space. Male removals revealed do not position territories solely be near mates, but spawn whichever occupies their area. Responses confirmed intrasexual competition restricts location amount space occupied some females. Group formation suggests, however, costs are so high prevent occupation adjacent territories. Instead, joining may promote dependable spawning opportunities for restricted burrows predator avoidance. males acquire mates. Males did not, from moving other when spaces made vacant experimentally. abandon all removed. Also, unmated large those many three These results support resource hypothesis. Monopolization multiple is only feasible, because reasons probably related Therefore, aspects harem also consistent We argue dichotomy between apply well group-living fish where site-restricted egg production iterated year-round.